#include <iostream>   //对应 C里的 stdio.h
#include <string> //C ++ string 类头文件
#include <cstring> //string.h  C 字符串相关函数头文件
using namespace std;

class A{
	 int n;
	 static int m;
public:
	A(){ n = m = 0; }
	A(int n, int m){ this->n = n; this->m = m; }
	void show(){ cout << "n:" << n << ",m:" << m << endl; }
	void setM(int x){ m = x; }
};
//静态成员必须类外初始化
int A::m = 1;


int main(){
	A a(1, 2),b(3,4);
	a.show();
	b.show();

	a.setM(567); 
	a.show(); b.show();
	b.setM(789);
	a.show(); b.show();


	while (1);
	return 0;
}